A ventilation apparatus that blows air into a vehicle compartment of a vehicle using Coanda effect is known.
For example, Patent Literature 1 discloses a ventilation apparatus disposed on a ceiling of a vehicle. In the ventilation apparatus, air blowing from a first blowing outlet flows along an outer surface of a duct by Coanda effect and flows toward a rear side of the vehicle while drawing air flowing around the air. As a result, the air is supplied to the vehicle compartment in a state that a volume of the air supplied to the vehicle compartment is larger than a volume of the air at a time of being blown from the first blowing outlet.
The ventilation apparatus of Patent Literature 1 further has a second blowing outlet other than the first blowing outlet, and the second blowing outlet blows air downward. The second blowing outlet blows the air such that the air joins, from an upper side, air blown from the first blowing outlet. The ventilation apparatus can change a flow direction of air in a longitudinal direction of the vehicle by changing a balance between flow rates of air blowing from the first blowing outlet and the second blowing outlet respectively. The ventilation apparatus of Patent Literature 1 thus does not need to have a member such as a resister that is provided on a ceiling of the vehicle to change a flow direction of air in the longitudinal direction.